In a mechanical returnless fuel system (MRFS), a fuel pump motor is energized by the maximum vehicle battery voltage for operating the fuel pump motor at a single speed in contrast to an electronic returnless fuel system (ERFS) which typically utilizes a computer or standalone module to electrically control the duty cycle of the fuel pump motor to provide the precise amount of fuel as demanded. All MRFS are relay switched. An advantage of the MRFS is that the MFRS is less costly than the ERFS.
A diode is provided across the power leads for the fuel pump motor at a location remote from the flange that is mounted to a fuel tank. The diode cannot be incorporated into the fuel pump, disposed in the fuel tank, due to exposure of the diode to the conductive and corrosive fuel.
Thus, there is a need to provide an MRFS that has a diode provided on an electrical connector associated with the flange, with the diode being sealed from the corrosive fuel.